The present application is directed to instruments and methods for moving a vertebral rod within a patient and into a bone anchor attached to a vertebral member and, more particularly, to instruments with an asymmetrical shape to facilitate insertion into the patient and movement of the vertebral rod into the bone anchor.
The spine is divided into four regions comprising the cervical, thoracic, lumbar, and sacrococcygeal regions. The cervical region includes the top seven vertebral members identified as C1-C7. The thoracic region includes the next twelve vertebral members identified as T1-T12. The lumbar region includes five vertebral members L1-L5. The sacrococcygeal region includes nine fused vertebral members that form the sacrum and the coccyx. The vertebral members of the spine are aligned in a curved configuration that includes a cervical curve, thoracic curve, and lumbosacral curve. Intervertebral discs are positioned between the vertebral members and permit flexion, extension, lateral bending, and rotation.
Elongated members may be attached to the vertebral members to various reasons such as to provide support, redirect stresses over a wider area away from a damaged or defective region, and restore the spine to its proper alignment. The elongated members are secured to one or more vertebral members through connectors. The connectors include a receiver that receives the elongated member, and an anchor to anchor into the vertebral member.
Instruments are needed to insert or reduce the elongated members into the anchors. The instruments should be sized and shape for insertion into the patient and connection to the bone anchors. The instruments should be designed for effective and efficient movement of the vertebral rod into the anchor.